Battery icon flashes between using battery and using power adapter in macbook

Hi,

I have a MacBook Pro which I bought in Feb 2018. It seems something wrong with the power system of my Mac since the last week. When I plug in the power adapter on my MBP, it should charge the battery. However, the battery won't charge, and the battery icon flashes. The power system switches between the battery and power adapter and the charging sound beeping continuously.

I took a short video to show what happens. ****

Does anyone know how to fix the problem?

Cheers,

Thushi

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